I have a 89 Sunbird eurosport with a 4.3L OMC/Cobra. I replaced the belts when I bought this with the same size that was on it. My problem is I think the belts that where on it are to narrow. They sit way down in the pulley grooves and wear excessively. Does anyone know where I can find a cross-ref for belts using OMC #'s. Or better yet, know which belts I need (I have power steering also, so I need both belts) I have tried NAPA and about every belt manufacturer website I can find. My original OMC parts list doesn't give belt sizes, just OMC #'s.